DESCRIPTION:(adapted from Investigator's abstract) Recent studies demonstrate that the immune system plays an important role in coronary artery disease (CAD). Research also shows that psychological factors such as major depressive disorder and acute mental stress are involved in the clinical progression of CAD. Depression is associated with higher levels of immune parameters that play a role in CAD (cytokines, markers of low grade inflammation, infectious pathogen burden, and adhesion molecules), and most of these measures also increase in response to acute physical and mental stress. The pathophysiological mechanisms linking depression and mental stress with adverse cardiovascular outcomes may therefore be mediated by immunological factors. The proposed research will examine clinical outcomes in patients who undergo percutaneous coronary revascularization, because a major problem remains the frequent (20 percent-40 percent) occurrence of coronary restenosis and new cardiac events in the 6 months after the intervention. These adverse outcomes have substantial impact on the costs of medical care and patients' quality of life. Since previous research has not examined the role of behaviorally-induced changes in immune parameters in the prediction of CAD progression, the following immunological measures will be examined: cytokines (IL-1B, IL-4, IL-6, IFNy, TNFa), acute phase proteins (CRP, fibrinogen), lymphocyte counts and differential, adhesion molecules (ICAM-1, LFA, L-selectin), and a composite measure of pathogen burden (CNV, H. pylori, C. pneumoniae). Using a longitudinal design, this project will determine the time course of changes in depression and changes in immune parameters. Moreover, the present study will determine the contribution of behavioral and immunological factors in the clinical progression of coronary disease following coronary angioplasty. These data may therefore improve the identification of patients at risk for recurrent cardiac events and restenosis after coronary angioplasty, and provide further understanding of the pathophysiological mechanisms involved in coronary disease progression.